mirror of
https://github.com/astral-sh/ruff.git
synced 2025-08-09 21:28:21 +00:00
Rename Red Knot (#17820)
This commit is contained in:
Micha Reiser
GitHub
parent
e6a798b962
commit
b51c4f82ea
1564 changed files with 1598 additions and 1578 deletions
|
|
@ -0,0 +1,293 @@
|
|||
# `typing.dataclass_transform`
|
||||
|
||||
```toml
|
||||
[environment]
|
||||
python-version = "3.12"
|
||||
```
|
||||
|
||||
`dataclass_transform` is a decorator that can be used to let type checkers know that a function,
|
||||
class, or metaclass is a `dataclass`-like construct.
|
||||
|
||||
## Basic example
|
||||
|
||||
```py
|
||||
from typing_extensions import dataclass_transform
|
||||
|
||||
@dataclass_transform()
|
||||
def my_dataclass[T](cls: type[T]) -> type[T]:
|
||||
# modify cls
|
||||
return cls
|
||||
|
||||
@my_dataclass
|
||||
class Person:
|
||||
name: str
|
||||
age: int | None = None
|
||||
|
||||
Person("Alice", 20)
|
||||
Person("Bob", None)
|
||||
Person("Bob")
|
||||
|
||||
# error: [missing-argument]
|
||||
Person()
|
||||
```
|
||||
|
||||
## Decorating decorators that take parameters themselves
|
||||
|
||||
If we want our `dataclass`-like decorator to also take parameters, that is also possible:
|
||||
|
||||
```py
|
||||
from typing_extensions import dataclass_transform, Callable
|
||||
|
||||
@dataclass_transform()
|
||||
def versioned_class[T](*, version: int = 1):
|
||||
def decorator(cls):
|
||||
# modify cls
|
||||
return cls
|
||||
return decorator
|
||||
|
||||
@versioned_class(version=2)
|
||||
class Person:
|
||||
name: str
|
||||
age: int | None = None
|
||||
|
||||
Person("Alice", 20)
|
||||
|
||||
# error: [missing-argument]
|
||||
Person()
|
||||
```
|
||||
|
||||
We properly type-check the arguments to the decorator:
|
||||
|
||||
```py
|
||||
from typing_extensions import dataclass_transform, Callable
|
||||
|
||||
# error: [invalid-argument-type]
|
||||
@versioned_class(version="a string")
|
||||
class C:
|
||||
name: str
|
||||
```
|
||||
|
||||
## Types of decorators
|
||||
|
||||
The examples from this section are straight from the Python documentation on
|
||||
[`typing.dataclass_transform`].
|
||||
|
||||
### Decorating a decorator function
|
||||
|
||||
```py
|
||||
from typing_extensions import dataclass_transform
|
||||
|
||||
@dataclass_transform()
|
||||
def create_model[T](cls: type[T]) -> type[T]:
|
||||
...
|
||||
return cls
|
||||
|
||||
@create_model
|
||||
class CustomerModel:
|
||||
id: int
|
||||
name: str
|
||||
|
||||
CustomerModel(id=1, name="Test")
|
||||
```
|
||||
|
||||
### Decorating a metaclass
|
||||
|
||||
```py
|
||||
from typing_extensions import dataclass_transform
|
||||
|
||||
@dataclass_transform()
|
||||
class ModelMeta(type): ...
|
||||
|
||||
class ModelBase(metaclass=ModelMeta): ...
|
||||
|
||||
class CustomerModel(ModelBase):
|
||||
id: int
|
||||
name: str
|
||||
|
||||
CustomerModel(id=1, name="Test")
|
||||
|
||||
# error: [missing-argument]
|
||||
CustomerModel()
|
||||
```
|
||||
|
||||
### Decorating a base class
|
||||
|
||||
```py
|
||||
from typing_extensions import dataclass_transform
|
||||
|
||||
@dataclass_transform()
|
||||
class ModelBase: ...
|
||||
|
||||
class CustomerModel(ModelBase):
|
||||
id: int
|
||||
name: str
|
||||
|
||||
# TODO: this is not supported yet
|
||||
# error: [unknown-argument]
|
||||
# error: [unknown-argument]
|
||||
CustomerModel(id=1, name="Test")
|
||||
```
|
||||
|
||||
## Arguments to `dataclass_transform`
|
||||
|
||||
### `eq_default`
|
||||
|
||||
`eq=True/False` does not have a observable effect (apart from a minor change regarding whether
|
||||
`other` is positional-only or not, which is not modelled at the moment).
|
||||
|
||||
### `order_default`
|
||||
|
||||
The `order_default` argument controls whether methods such as `__lt__` are generated by default.
|
||||
This can be overwritten using the `order` argument to the custom decorator:
|
||||
|
||||
```py
|
||||
from typing_extensions import dataclass_transform
|
||||
|
||||
@dataclass_transform()
|
||||
def normal(*, order: bool = False):
|
||||
raise NotImplementedError
|
||||
|
||||
@dataclass_transform(order_default=False)
|
||||
def order_default_false(*, order: bool = False):
|
||||
raise NotImplementedError
|
||||
|
||||
@dataclass_transform(order_default=True)
|
||||
def order_default_true(*, order: bool = True):
|
||||
raise NotImplementedError
|
||||
|
||||
@normal
|
||||
class Normal:
|
||||
inner: int
|
||||
|
||||
Normal(1) < Normal(2) # error: [unsupported-operator]
|
||||
|
||||
@normal(order=True)
|
||||
class NormalOverwritten:
|
||||
inner: int
|
||||
|
||||
NormalOverwritten(1) < NormalOverwritten(2)
|
||||
|
||||
@order_default_false
|
||||
class OrderFalse:
|
||||
inner: int
|
||||
|
||||
OrderFalse(1) < OrderFalse(2) # error: [unsupported-operator]
|
||||
|
||||
@order_default_false(order=True)
|
||||
class OrderFalseOverwritten:
|
||||
inner: int
|
||||
|
||||
OrderFalseOverwritten(1) < OrderFalseOverwritten(2)
|
||||
|
||||
@order_default_true
|
||||
class OrderTrue:
|
||||
inner: int
|
||||
|
||||
OrderTrue(1) < OrderTrue(2)
|
||||
|
||||
@order_default_true(order=False)
|
||||
class OrderTrueOverwritten:
|
||||
inner: int
|
||||
|
||||
# error: [unsupported-operator]
|
||||
OrderTrueOverwritten(1) < OrderTrueOverwritten(2)
|
||||
```
|
||||
|
||||
### `kw_only_default`
|
||||
|
||||
To do
|
||||
|
||||
### `field_specifiers`
|
||||
|
||||
To do
|
||||
|
||||
## Overloaded dataclass-like decorators
|
||||
|
||||
In the case of an overloaded decorator, the `dataclass_transform` decorator can be applied to the
|
||||
implementation, or to *one* of the overloads.
|
||||
|
||||
### Applying `dataclass_transform` to the implementation
|
||||
|
||||
```py
|
||||
from typing_extensions import dataclass_transform, TypeVar, Callable, overload
|
||||
|
||||
T = TypeVar("T", bound=type)
|
||||
|
||||
@overload
|
||||
def versioned_class(
|
||||
cls: T,
|
||||
*,
|
||||
version: int = 1,
|
||||
) -> T: ...
|
||||
@overload
|
||||
def versioned_class(
|
||||
*,
|
||||
version: int = 1,
|
||||
) -> Callable[[T], T]: ...
|
||||
@dataclass_transform()
|
||||
def versioned_class(
|
||||
cls: T | None = None,
|
||||
*,
|
||||
version: int = 1,
|
||||
) -> T | Callable[[T], T]:
|
||||
raise NotImplementedError
|
||||
|
||||
@versioned_class
|
||||
class D1:
|
||||
x: str
|
||||
|
||||
@versioned_class(version=2)
|
||||
class D2:
|
||||
x: str
|
||||
|
||||
D1("a")
|
||||
D2("a")
|
||||
|
||||
D1(1.2) # error: [invalid-argument-type]
|
||||
D2(1.2) # error: [invalid-argument-type]
|
||||
```
|
||||
|
||||
### Applying `dataclass_transform` to an overload
|
||||
|
||||
```py
|
||||
from typing_extensions import dataclass_transform, TypeVar, Callable, overload
|
||||
|
||||
T = TypeVar("T", bound=type)
|
||||
|
||||
@overload
|
||||
@dataclass_transform()
|
||||
def versioned_class(
|
||||
cls: T,
|
||||
*,
|
||||
version: int = 1,
|
||||
) -> T: ...
|
||||
@overload
|
||||
def versioned_class(
|
||||
*,
|
||||
version: int = 1,
|
||||
) -> Callable[[T], T]: ...
|
||||
def versioned_class(
|
||||
cls: T | None = None,
|
||||
*,
|
||||
version: int = 1,
|
||||
) -> T | Callable[[T], T]:
|
||||
raise NotImplementedError
|
||||
|
||||
@versioned_class
|
||||
class D1:
|
||||
x: str
|
||||
|
||||
@versioned_class(version=2)
|
||||
class D2:
|
||||
x: str
|
||||
|
||||
# TODO: these should not be errors
|
||||
D1("a") # error: [too-many-positional-arguments]
|
||||
D2("a") # error: [too-many-positional-arguments]
|
||||
|
||||
# TODO: these should be invalid-argument-type errors
|
||||
D1(1.2) # error: [too-many-positional-arguments]
|
||||
D2(1.2) # error: [too-many-positional-arguments]
|
||||
```
|
||||
|
||||
[`typing.dataclass_transform`]: https://docs.python.org/3/library/typing.html#typing.dataclass_transform
|
||||
Loading…
Add table
Add a link
Reference in a new issue